A Unified Perspective of Unilateral Spatial Neglect

Abstract: The aim of this review is to provide a unified perspective of unilateral spatial neglect (USN). USN is a neurological disorder frequently observed following damage or diseases to the brain. It is particularly associated with strokes to specific anatomical structures within the right hemisphere. Patients with USN fail to respond to or orient towards stimuli located in the hemispace contralateral to the lesion. They also show peculiar behavioral manifestations. There are several distinct subtypes of USN which can affect sensory or motor modalities, spatial representations, the range of space, or pure imagery. This disorder can appear in any sensory modality but the majority of studies have investigated the visual aspect of USN in these subtypes. Theoretical proposals are supported by empirical evidence deriving from neuroimaging which distinguish between these subtypes of USN. Thus, the heterogeneity of the disorder is evident and clinical assessment methods face great difficulties while prevalence rates vary. The neural pathways of spatial attention distinguish between the ventral and dorsal visual streams, both with distinct functional roles and anatomical bases. Prism adaptation (PA) is a common rehabilitation technique among many others and has shown positive effects on USN while having some limitations. A general discussion and concluding remarks are presented in the final section followed by future research suggestions.